Shifting Environmental Ranges and Biome Potential According to the Whittaker Relationship

Abstract:

Robert H. Whittaker classified biome types mainly as a function of Mean Annual Temperature (MAT) and Mean Annual Precipitation (MAP), resulting in the well-known Whittaker plot¹. This relationship is still being used to map biomes globally². The same inputs (MAT and MAP), augmented with a radiation proxy, are used in the resource-balance perspective for modeling large-scale vegetation productivity as a function of abiotic factors³. These two approaches, used in a temporally dynamic manner, provided us indicators of shifts in growth-limiting factors⁴ and associated environmental ranges of vegetation, which, in turn, are key indicators for the study of global change and biodiversity⁵.

We present a study in which we used the Whittaker relationship and CRU TS 3.22 climatic data to map regions that showed variable biome potential. These regions are likely to indicate ecotones – i.e. interactions zones between biomes – that have been subject to abiotic change and where a change in the vegetation system can be anticipated. At the same time, we used remotely sensed data (GIMMS v3g 1982-2012) to study gradients in vegetation dynamics in these zones. Preliminary results show strongest environmental shifts in northern ecotones, e.g. on the tundra – boreal boundary, and associated changes in climatic growth-limiting factors⁴.

[1] Whittaker RH (1975) Communities and Ecosystems, Macmillan, 385p.
[2] Ricklefs RE (2008) The Economy of Nature, W. H. Freeman, 620p.
[3] Field CB, Randerson JT, Malmström CM (1995) Global net primary production: Combining ecology and remote sensing. Remote Sensing of Environment, 51, 74-88.
[4] Schenkel D, Garonna I, De Jong R, Schaepman ME (this conference) Linking Land Surface Phenology and Growth Limiting Factor Shifts over the Past 30 Years.
[5] University of Zurich Research Priority Program on Global Change and Biodiversity, http://www.gcb.uzh.ch